DNAs coding for flavone synthase, methods of using flavone synthase DNAs, and plants, flowers, and vectors containing flavone synthase DNAs

Abstract

A DNA encoding a flavone synthase that synthesizes flavones from flavanones, vectors containing said DNAs, and plants expressing same are disclosed. Methods of producing the protein which synthesizes flavones from flavanones, methods of altering the composition of flavonoids or the amount of flavonoids in a plant, methods of altering flower color and plant photosensitivity, and methods of controlling interactions between plants expressing the protein and microorganisms are also disclosed.

1. An isolated DNA or RNA encoding a protein, wherein said protein has an activity of synthesizing flavones from flavanones, further wherein the protein has the amino acid sequence as shown in SEQ ID NO: 2. 
     
     
       2. An isolated DNA having the nucleotide sequence of SEQ ID NO: 1. 
     
     
       3. A vector comprising the isolated gene DNA according to  claim 1 . 
     
     
       4. A plant host transformed by the vector according to  claim 3 . 
     
     
       5. A method of producing a protein with flavone-synthesizing activity, comprising culturing or growing a plant host according to  claim 4 , and recovering said protein from said plant host. 
     
     
       6. A plant, a progeny thereof, or a tissue thereof, wherein said plant, progeny or tissue comprises the isolated DNA or RNA of  claim 1 . 
     
     
       7. A cut flower from the plant or the progeny thereof according to  claim 6  comprising said isolated DNA or RNA. 
     
     
       8. A method of altering a composition of flavonoids or amount thereof, or both the composition and amount in a plant host comprising:
 introducing a vector having the DNA according to  claim 1  into a plant host; 
 culturing or growing said plant host; and 
 recovering said flavones; 
 
       wherein said flavones are included in a composition of flavonoids. 
     
     
       9. The method according to  claim 8 , wherein said DNA is inserted in the vector. 
     
     
       10. A method of altering the amount of a flavone in a plant host comprising:
 introducing a vector having the DNA according to  claim 1  into a plant host; 
 culturing or growing said host, wherein said flavone synthase gene is expressed and amount of flavone altered. 
 
     
     
       11. A method of altering the color of a flower comprising:
 introducing a vector having the DNA according to  claim 1  into a flower plant; 
 culturing or growing said flower plant, wherein said DNA is expressed and expression of said DNA alters the flower color in said flower plant. 
 
     
     
       12. A method of bluing the color of a flower comprising:
 introducing a vector having the DNA according to  claim 1  into a flower plant; and 
 culturing or growing said flower plant, wherein the DNA is expressed and flavone is produced in the flower plant. 
 
     
     
       13. A method of reddening the color of a flower comprising:
 introducing a vector having the DNA according to  claim 1  into a flower plant; and 
 culturing or growing said flower plant, wherein expression of the DNA is suppressed in the flower plant. 
 
     
     
       14. A method of altering the photosensitivity of a plant comprising:
 introducing a vector having the DNA according to  claim 1  into a plant; and 
 culturing or growing said plant, wherein the DNA is expressed. 
 
     
     
       15. A method of controlling the interaction between a plant and microorganisms comprising:
 introducing a vector having the DNA according to  claim 1  into a plant; and 
 culturing or growing said plant, wherein the DNA is expressed and flavone produced in the plant. 
 
     
     
       16. A method of altering a composition of flavones or amount thereof, or both the composition and amount in a plant or tissue thereof comprising:
 introducing a vector having the DNA according to  claim 1  into a plant or tissue thereof; and 
 culturing or growing said plant or tissue, whereby the DNA is expressed in said plant or tissue. 
 
     
     
       17. A method of suppressing flavone synthesis in a plant or tissue thereof, comprising:
 introducing a vector having the DNA according to  claim 1  into a plant or tissue thereof; and 
 culturing or growing said plant or tissue, whereby expression of the DNA is suppressed in said plant. 
 
     
     
       18. A method of increasing an amount of flavone in a flower petal, comprising:
 introducing a vector having the DNA according to  claim 1  into a plant or tissue thereof; and 
 culturing or growing said plant or tissue, whereby the DNA is expressed in said plant. 
 
     
     
       19. A method of decreasing an amount of flavone in a flower petal, comprising:
 introducing a vector having the DNA according to  claim 1  into a plant or tissue thereof; and 
 culturing or growing said plant or tissue, whereby expression of the DNA is suppressed in said plant. 
 
     
     
       20. A method of synthesizing a flavone from flavanone comprising:
 introducing a vector having the DNA according to  claim 1  into a plant host having flavanones; 
 culturing or growing said plant host, whereby said DNA is expressed in said plant host to produce a flavone synthase; and 
 said flavone synthase synthesizes flavone from said flavanone. 
 
     
     
       21. A method for producing a flavone synthase comprising:
 introducing a vector having the DNA according to  claim 1  into a plant host; and 
 culturing or growing said plant host, whereby said DNA is expressed in said plant host to produce a flavone synthase.